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The tensioner pulley is the core adjustment component of the engine belt drive system.
The uses are as follows:
? Maintain belt tension
Automatically compensate for belt elongation (rubber naturally stretches about 2-3% due to aging)
Prevent slippage: ensure friction between the belt and the pulley (typical tension value: 400-600N)
? Buffer vibration impact
Absorb instantaneous speed fluctuations of the crankshaft/accessory wheel (such as air conditioning compressor start and stop)
Reduce belt vibration amplitude (controlled within ±2mm)
? Extend system life
Avoid overtightening (causing premature bearing wear) or overloosening (causing slippage and abnormal noise)
Equilibrium sharing of multiple accessory loads (generator/water pump/air conditioner, etc.)
Failure chain reaction
?? Tensioner failure ? belt slippage/breakage ? accessory system stoppage (water pump/generator/air conditioner) ? engine overheating/power failure
link:https://www.onodetruckparts.com/search/tensioner.html
Tensioner Pulley 3979979 20935521 3979579 20739751 21422765 21819687 7403979979